Isolation, identification, and pathogenicity of porcine epidemic diarrhea virus

Swine interferon-induced transmembrane proteins inhibit porcine epidemic diarrhea virus replication

Porcine epidemic diarrhea (PED) caused by porcine epidemic diarrhea virus (PEDV) has significantly harmed the global pig industry economically. Interferons can induce the expression of interferon-stimulated genes (ISGs) that encode various natural antiviral immune effectors. Notably, swine interferon-induced transmembrane proteins (SwIFITMs) have not been thoroughly investigated in the context of PEDV. In the present research, we explored the anti-PEDV effects of SwIFITMs. Both interferon and PEDV were found to upregulate swine IFITM mRNA levels. Swine IFITM knockdown results showed that SwIFITM1a, -1b, and -2 most significantly reduced PEDV replication. By overexpressing SwIFITMs and establishing a SwIFITM-expressing Vero cell line, we identified SwIFITM2 as having the most pronounced anti-PEDV effect. SwIFITM2 inhibited PEDV entry phase. Additionally, SwIFITM2 interacted with PEDV S2 and N proteins in a dose-dependent manner. Furthermore, it exhibited high co-localization with caveolin-1, while demonstrating the lowest co-localization ratio with clathrin. Upon infection with PEDV, the co-localization of caveolin-1 and PEDV S2 or N protein significantly increased compared with control in the presence of SwIFITM2, indicating that SwIFITM2 may play an antiviral role by confining PEDV within caveolin-1. This study elucidates the anti-PEDV mechanisms of SwIFITMs, providing critical insights into their potential roles in viral pathogenesis and host defense.

Ginsenoside Rb1 inhibits porcine epidemic diarrhea virus replication through suppressing S1 protein mediated the MAPK/ERK pathway and reducing apoptosis

Porcine epidemic diarrhea virus (PEDV) causes vomiting, dehydration, and diarrhea in piglets, seriously threatening their survival and development and causing huge economic losses to the global pig industry. Current PEDV control relies on vaccines, however, the high mutation rate of PEDV limits vaccine effectiveness, highlighting the need for new antiviral drugs. This study investigated the pharmacological effects of ginsenoside Rb1 (GRb1) on PEDV using network pharmacology, as well as GO and KEGG analyses, to predict its role in modulating the MAPK/ERK pathway. GRb1 downregulated the MAPK/ERK pathway activated by PEDV infection and reduced levels of the apoptotic protein cleaved-caspase-3, thus inhibiting PEDV-induced apoptosis and demonstrating antiviral properties. Further screening showed that the PEDV S1 protein promotes AP-1 nuclear entry and upregulates the MAPK/ERK pathway to induce apoptosis, a process reversed by GRb1. Further in vivo studies revealed that GRb1 treatment significantly reduced viral load in piglet intestinal tissues and anal swabs. GRb1 also alleviated clinical symptoms and intestinal damage in infected piglets, improving their survival rate while also downregulating the levels of inflammatory factors (IL-1β, IL-6, IL-8, and TNF-α). This study is the first to demonstrate that GRb1 effectively inhibits PEDV, uncovering its potential mechanism of action and providing a promising new approach for antiviral treatment in veterinary medicine.

Advances in porcine epidemic diarrhea virus research: genome, epidemiology, vaccines, and detection methods

Porcine epidemic diarrhea (PED) is a highly contagious intestinal disease caused by the porcine epidemic diarrhea virus (PEDV). The economic impact of PEDV on the global pig industry has been significant, resulting in considerable losses. This paper presents a review of the latest research progress on PEDV genome, molecular epidemiology, vaccine development, and molecular detection methods. It was determined that the genetic diversity of the PEDV spike (S) gene was closely associated with the epidemiological trend of PEDV. The prevalence of S gene variants of different genotypes exhibited variability across regions and pig populations. Epidemiological analyses have demonstrated that PEDV can be transmitted via multiple routes, including direct contact, airborne aerosol, and water source contamination. With regard to vaccine research, the available vaccines can be classified into several categories, including live-attenuated vaccines, inactivated vaccines, subunit vaccines, bacterial vector vaccines, viral vector vaccines, mRNA vaccines, etc. Each of these has distinctive characteristics in terms of immunogenicity, protection efficiency, and safety. Molecular detection methods, including PCR-based methods, isothermal amplification techniques, immunological assays, and biosensors, play an important role in the diagnosis and monitoring of PEDV. Furthermore, this paper examines the current developments in PEDV research and identifies the key areas of future investigation. The objective of this paper is to establish a theoretical foundation for the prevention and control strategies of PED, and to provide a point of reference for further research on the genomics, epidemiology, vaccine development and detection methods of PEDV.

RETRACTED: Andrographolide inhibits porcine epidemic diarrhea virus by inhibiting the JAK2-STAT3 pathway and promoting apoptosis

This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/policies/article-withdrawal). This article has been retracted at the request of the Authors and the Editor-in-Chief. After acceptance of the manuscript, the Authors discovered that the animal experimental control group was infected, which makes the findings presented in the paper invalid. Specifically, they noted that the intestinal villus in pathological tissue sections of the negative group exhibited slight shedding, resembling PEDV infection. Further investigation revealed that the pig farms supplying the experimental animals experienced occasional outbreaks of PEDV infections. The Editor-in-Chief agreed that this article must be retracted and no longer has any confidence in the validity of the data presented in the manuscript.

RpIFN-λ1 alleviates the clinical symptoms of porcine epidemic diarrhea

Porcine epidemic diarrhea (PED), caused by the porcine epidemic diarrhea virus (PEDV), primarily affects the jejunum and ileum of pigs. Interferons, glycoproteins with high species specificity and potent antiviral activity, are crucial in defending against viral infections. Unlike other interferons, interferon-lambda (IFN-λ) mainly acts on mucosal epithelial cells and exhibits robust antiviral activity at mucosal surfaces. However, the high cost limits the use of naturally extracted interferons in farming. In this study, we expressed recombinant porcine interferon-lambda 1 (rpIFN-λ1) in eukaryotic cells, demonstrating effective antiviral activity against PEDV in Vero E6 and IPI-FX cells. In vivo, rpIFN-λ1 alleviated clinical symptoms and intestinal damage, enhanced antioxidant capacity, reduced inflammation, and significantly improved the survival rate of piglets following PEDV infection. Both in vitro and in vivo studies confirmed that rpIFN-λ1 upregulated interferon-stimulated genes (ISGs) via the JAK-STAT pathway, thereby exerting antiviral effects. In conclusion, rpIFN-λ1 significantly inhibited PEDV replication and alleviated clinical symptoms. The selectivity of rpIFN-λ1 for intestinal cells and its ability to reduce viral shedding suggest that this agent is a promising antiviral for enteric viruses such as PEDV. Our findings highlight rpIFN-λ1 as a cost-effective, efficient, and novel strategy for antiviral treatment of PEDV.

Anti-virus activity and mechanisms of natural polysaccharides from medicinal herbs

There has been a sudden increase in viral diseases, such as coronavirus disease 2019 (COVID-19), causing significant harm to human and animal well-being, as well as economic development. Medicinal herbs, with a history of thousands of years in clinical use, contain versatile polysaccharides as one of their primary compounds. This review offers an overview of the antiviral effects of polysaccharides from medicinal herbs on viruses in humans, poultry, swine and aquaculture in recent years. The mechanism of these antiviral polysaccharides, involved in hindering various stages of the viral life cycle thereby blocking virus infection, is summarized. The review also explores other underlying mechanisms of antiviral effects, such as enhancing the immune response, regulating inflammatory reactions, balancing gut flora, reducing oxidative stress, and suppressing apoptosis through various corresponding signaling pathways. The structure-function relationships discussed in this article also aid in understanding the antiviral mechanism of natural polysaccharides, indicating the need for more in-depth research and analysis. Natural polysaccharides from medicinal herbs have emerged as valuable resources in the fight against viral infections, exhibiting high effectiveness. This review emphasizes the promising role of polysaccharides from medicinal herbs as potential candidates for blocking viral infections in humans and animals.

Nucleotide metabolism-related host proteins RNA polymerase II subunit and uridine phosphorylase 1 interacting with porcine epidemic diarrhea virus N proteins affect viral replication

Porcine epidemic diarrhea virus (PEDV) is a highly infectious pathogen that targets pig intestines to cause disease. It is globally widespread and causes huge economic losses to the pig industry. PEDV N protein is the protein that constitutes the core of PEDV virus particles, and most of it is expressed in the cytoplasm, and a small part can also be expressed in the nucleus. However, the role of related proteins in host nucleotide metabolic pathways in regulating PEDV replication have not been fully elucidated. In this study, PEDV-N-labeled antibodies were co-immunoprecipitated and combined with LC-MS to screen for host proteins that interact with N proteins. Bioinformatics analyses showed that the selected host proteins were mainly enriched in metabolic pathways. Moreover, co-immunoprecipitation and confocal microscopy confirmed that the second-largest subunit of RNA polymerase II (RPB2) and uridine phosphorylase 1 (UPP1) interacted with the N protein. RPB2 is the main subunit of RNA polymerase II and plays an important role in eukaryotic transcription. UPP1 is an enzyme that catalyzes reversible phosphorylation of uridine to uracil and ribo-1-phosphate to promote catabolism and bio anabolism. RPB2 overexpression significantly promoted viral replication, whereas UPP1 overexpression significantly inhibited viral replication. Studies on interactions between the PEDV N and host proteins are helpful in elucidating the pathogenesis and immune escape mechanism of PEDV.

Identification of host proteins interacting with the E protein of porcine epidemic diarrhea virus

Introduction

Porcine epidemic diarrhea (PED) is an acute, highly contagious, and high-mortality enterophilic infectious disease caused by the porcine epidemic diarrhea virus (PEDV). PEDV is globally endemic and causes substantial economic losses in the swine industry. The PEDV E protein is the smallest structural protein with high expression levels that interacts with the M protein and participates in virus assembly. However, how the host proteins interact with E proteins in PEDV replication remains unknown.

Methods

We identified host proteins that interact with the PEDV E protein using a combination of PEDV E protein-labeled antibody co-immunoprecipitation and tandem liquid-chromatography mass-spectroscopy (LC-MS/MS).

Results

Bioinformatical analysis showed that in eukaryotes, ribosome biogenesis, RNA transport, and amino acid biosynthesis represent the three main pathways that are associated with the E protein. The interaction between the E protein and isocitrate dehydrogenase [NAD] β-subunit (NAD-IDH-β), DNA-directed RNA polymerase II subunit RPB9, and mRNA-associated protein MRNP 41 was validated using co-immunoprecipitation and confocal assays. NAD-IDH-β overexpression significantly inhibited viral replication.

Discussion

The antiviral effect of NAD-IDH-β suggesting that the E protein may regulate host metabolism by interacting with NAD-IDH-β, thereby reducing the available energy for viral replication. Elucidating the interaction between the PEDV E protein and host proteins may clarify its role in viral replication. These results provide a theoretical basis for the study of PEDV infection mechanism and antiviral targets.